232-13 Carbon Balance and Metabolic Changes of Kentucky Bluegrass in Responses to Elevated Temperature and Carbon Dioxide Concentration.

See more from this Division: C02 Crop Physiology and Metabolism
See more from this Session: Graduate Student Oral Competition

Tuesday, November 5, 2013: 11:15 AM
Marriott Tampa Waterside, Room 1

Yali Song1, Jingjin Yu2, Patrick Burgess1 and Bingru Huang1, (1)Plant Biology and Pathology, Rutgers University, New Brunswick, NJ
(2)No. 1 Weigang, Xuanwu District, Nanjing Agricultural University, Nanjing, Jiangsu, CHINA
Abstract:
Elevated CO2 concentration has been found to mitigate the adverse effects of increasing temperatures in various plant species, including cool-season grass species.  The objective of this study was to investigate metabolic factors associated with the interactive effects of elevated CO2 and increasing temperatures on cool-season turfgrass species.  Kentucky bluegrass (cv. ‘Baron’) plants were grown in growth chambers with ambient CO2 (400 ppm) and elevated CO2 (800 ppm) and day/night temperature treatments of 15/12, 20/17, 25/22, 30/27, 35/32 oC under well-watered conditions.  Increasing temperatures at and above 25 oC resulted in significant decline in turf quality.  Plants at elevated CO2 consistently had significantly higher turf quality at all temperature regimes than those at ambient CO2.  Single-leaf photosynthesis (Pn) decreased while respiration rate (R) increased with increasing temperatures and respiration rate exceeded Pn at and above 25 oC.  Elevated CO2 significantly suppressed the increases in respiration rate, particularly at 30/27 and 35/32 oC, and resulted in higher Pn/R ratio.  The content of soluble sugars (i.e. glucose and sucrose) and organic acids (i.e. citric acid and oxalic acid) decreased with increasing temperatures above 20/17 oC under both ambient and elevated CO2.  Elevated CO2 treatment mitigated the decline in the content of those soluble sugars and amino acids under high temperatures. Elevated CO2 also increased the accmulation of animo acids (i.e. alanine, serine, aspartic acid, and threonine) under different temperature regimes. The results suggested that the positive effects of elevated CO2 could be assocaited with the maintenance of carbon balance and accumulation of key metabolites regulating plant growth.

See more from this Division: C02 Crop Physiology and Metabolism
See more from this Session: Graduate Student Oral Competition